Evaporation-induced self-assembly (EISA) synthesized mesoporous bimetallic oxides (MBOs) enabling enhanced co-uptake of arsenate and fluoride from water

BACKGROUND Simultaneous removal of arsenic and fluoride anions from water by adsorption remains a challenge for environmental remediation practice. To address this issue, four mesoporous bimetallic oxides (MBOs) were prepared via the evaporation-induced self-assembly (EISA) method and studied as adsorbents for the co-uptake of arsenate (As(V)) and fluoride (F-) from synthetic wastewater. Adsorption envelope and equilibrium experiments were performed to investigate the adsorption behaviors and properties. RESULTS These composites possessed high surface areas (e.g. 200 m(2) g(-1) for meso-Ti/Al) and well-defined mesopores, enabling high adsorption capacities for both As(V) and F-. The maximum adsorption capacities of mesoporous titanium-lanthanum oxide (meso-Ti/La) were as high as 81.42 mg g(-1) and 44.37 mg g(-1) for As(V) and F-, respectively. Surface complexation modeling indicates that As(V) removal mainly involved bidentate surface complexation with surface equivalent to Me-OH, while F- was retained by formation of monodentate surface complexes. CONCLUSION The removal mechanisms were confirmed by X-ray photoelectron spectroscopy. These MBOs were found to be effective for simultaneous removal of arsenic and fluoride from water. This study also demonstrated that the incorporation of multi-components and mesoporosity into one composite is an efficient strategy for design and application of high-efficiency adsorbents for environmental remediation of aqueous contaminants. (c) 2018 Society of Chemical Industry